How to get the index of the element in javascript?

Question

The NodeList don\'t have a indexOf(element) method? So, how can I get the element index?

Answer 1

By iterating over the elements, and checking if it matches.

Generic code that finds the index of the element within it's parents childNodes collection.

function index(el) {
    var children = el.parentNode.childNodes,
        i = 0;
    for (; i < children.length; i++) {
        if (children[i] == el) {
            return i;
        }
    }
    return -1;
}

Usage:

// should return 4
var idx = index(document.body.childNodes[4]);

EDIT: I can't delete an accepted answer, but @kennebec's answer below is much better, which I'll quote verbatim:

You can use Array.prototype.indexOf.call() like this

let nodes = document.getElementsByTagName('*');
Array.prototype.indexOf.call(nodes, document.body);